This isn't really a "yes or no" question. I don't feel the need to warm up, as shugging sort of warms me up as I get going with it. On the other hand, depending on your level of fitness, strength, flexibility, etc., you might want to limber up a bit before starting your shovelglove session. I also don't find it necessary to cool down afterwards... if you do, then do.

In the beginning, I suggest erring on the side of caution... warm up a little before shugging, get acquainted with the movements and pacing of the workout, and go from there. Have fun !_________________"The patient warrior is rewarded." (~Klingon proverb)

Probably couldn't hurt, but 14 minutes is all I can consistently bring myself to spare, and that would put me over the edge.

I have to say I've been surprised though at how "safe" shovelglove has been for me over these 14 years. I've never once injured myself, which is far more than I can say for my attempts at running. Maybe it's the reverse of that psychological seatbelt/airbag effect that makes people more likely to have car accidents: because swinging around a sledgehammer is so obviously dangerous, it's hard not to be careful.